Known by its military designation as the High Mobility Multi-purpose Wheeled Vehicle, the HMMWV is a lightweight, highly mobile, diesel-powered, four-wheel-drive tactical vehicle that uses a common chassis to carry a wide variety of military hardware ranging from machine guns to tube-launched, optically tracked, wire command-guided (TOW) anti-tank missile launchers. As a centerpiece of the Army's vehicular force modernization, HMMWVs are air transportable and droppable, and can be sling-loaded by helicopters. The HMMWV has a low profile (six feet tall), a wide stance (seven feet wide) and is 15 feet long. The HMMWV is constructed on a steel frame with boxed frame rails and five cross members constructed from high-grade alloy steel. The AM General-designed geared hub assembly in the power train doubles the torque to each wheel in the hub of the wheel. The M1097A2 series features a 6.5-liter Optimizer 6500 diesel engine built by AM General's subsidiary, General Engine Products.
The vehicle has either a 1 + 1 or 2 + 2 seating, depending on the model, on each side of the drivetrain, which is elevated, allowing the differentials to be raised. The modular design of the HMMWV allows it to be easily re-configured for many different uses. It must perform in a wide variety of terrain, from deserts to jungles, for long periods of time, with minimal maintenance. They meet all of these requirements while incorporating new standards of reliability for combat vehicles.

The 16-inch ground clearance of the HMMWV is an engineering feat considering that the vehicle stands only 72 inches high. Three HMMWVs can be carried in a C-130 Hercules transport aircraft and 15 in a C-5A Galaxy.
These proportions contribute to a stable, road-hugging truck that is very difficult to roll over.
Once the substructure is assembled, E-coating is applied to provide additional corrosion protection. Aluminum body panels are riveted and bonded together with technologically-advanced adhesives to provide additional strength. This also helps achieve 16 inches of ground clearance, far more than any other vehicle in its class. It is coupled to a four-speed automatic transmission and full-time four-wheel drive transfer case to provide the HMMWV with exceptional performance.
It has to carry its cargo and occupants in safety while dodging instruments of war — bullets, bombs and mines. They score high on Reliability, Availability, Maintainability and Durability (RAM-D) requirements and specifications.
Full-time four-wheel drive, independent suspension, steep approach and departure angles, 60 percent slope-climbing, 40 percent side slope and 60-inch water-fording capabilities combine with the high ground clearance to make the HMMWV an exceptional off-road vehicle.

In combat conditions, the HMMWV can be delivered by the Low Altitude Parachute Extraction System without the aircraft having to land. The use of a double A-arm independent suspension front and rear, coil springs and hydraulic double-acting shock absorbers gives the HMMWV unsurpassed mobility. The location of the crew on each side of the drivetrain also allows for a low center of gravity. During initial production tests, the new vehicle proved to be nearly twice as durable as the Army required. Four-wheel disc brakes are mounted inboard against the sides of the differentials both of which are located up, between the frame rails, protecting them from impact and debris. Torque-biasing differentials allow the vehicle to continue to move forward as long as any one wheel has traction. The current production Expanded Capacity Vehicle (ECV) model M1113 has a payload of 5,100 lbs.
The up-armored variant M1114 is produced by AM General with the armor package installed by O'Gara Hess and Eisenhart.